Brake-shoe



(No Model.)

W. W. WHITOOMB & F. P. COGGIN.

BRAKE SHOE.

Patented De0. 15, 1896.

IN VENTURE.

' ATT'Y UNITED STATES PATENT OFFICE.

WILLIAM W. \VHITOOMB, OF BROOKLIN E, AND FRANK F. OOGGIN, OF AKE- FIELD, MASSACHUSETTS, ASSIGNORS TO THE COMPOSITE BRAKE Sll'IOE COMPANY, OF BOSTON, MASSACHUSETTS.

BRAKE-SHOE.

SPECIFICATION forming part of Letters Patent No. 573,252, dated December 15, 1896. Application filed October 16, 1896- Serial No. 609,064. (No model.)

To aZl whom it may concern: cork is not open to the objections above re- Be it known that we, WILLIAM W. WVHIT- ferred to, as will be described, but, in addi- COMB, of Brookline, in the county of Norfolk, tion, gives increased braking effects, thereby and FRANK F. COGGIN, of Wakefield, in the particularly adapting such a brake-shoe for county of Middlesex, State of Massachusetts, use on cars which run at a high speed. 55

have invented an Improvement in Brake- Our invention therefore consists in a com- Shoes, of which the following description, in posite brake-shoe, such as will be pointed out connection with the accompanying drawings, in the claims at the end of this specification. is a specification, like letters on the drawings Figure 1 is a front elevation or face view representing like parts. of a composite brake-shoe embodying this in- 60 This invention relates to a clutch or brakevention; Fig. 2, a transverse section on the shoe especially adapted, among other uses, to line 2 2, Fig. 1; Fig. 3, an elevation of a modibe employed on railway-cars, and more parfied form of clutch or brake-shoe embodying ticularly steam or electric railway cars which this invention; and Fig. 4, a section on the run at a high speed. Prior to this invention line 4 4, Fig. 5 we are aware that compositebrake-shoes have Referring to the drawings, Figs. 1 and 2 been made of metal with wooden plugs in-, represent one form of brake-shoe applicable serted into suitable sockets or holes in the; for use with the flanged wheels of steam and said metal and locked therein by suitable deelectric railway cars, the said brake-shoe convices. Such brake-shoesare efficient for servsisting of a body a,havingits wheel-contacting 7o ice 011 street-railway cars which do not run. face a provided, as herein shown, with a pluat a very high speech but such brake-shoes. ralit-y of sockets, holes, or openings a which are more or less defective or deficient for use in the present instance extend but partially on railway-cars which run at a high speed, through the body a. In the present instance such as is obtained on steam-railroads and the sockets or holes a are shown as cylinalso on some branches of railways operating drical in form and in substantially the same with electricity. The defect or deficiency re- ,straight line with intervening openings a ferred to is due to the severe usage to which I which connect the adjacent sockets a so as the brake-shoe is put, for, owing to the high; to form a substantially continuous longitu- 0 speed of the car, great friction is createcL. dinal slot varying in width at intervals, the when the brake-shoes are applied to the rapsaid sockets and connecting openings being idly-revolving car-wheels, and this friction 1 located in that part of the face of the shoe creates great heat and subjects the wooden which is in the same plane as that part of the plugs to such heat as to rapidly shrink the; tread of the wheel worn by the rail. The

3 5 same to such extent that they are liable to besockets a in accordance with this invention, come loose in their sockets, notwithstanding are tilled with sections or blocks 1), of cork, the firm manner in which they are put into which, before being inserted into the sockets the said sockets, and as a result the wooden a are preferably of larger diameter or area 'plugs are liable to crumble and work out of than the said sockets, and which are there- 40 their sockets, and the usefulness of the shoe fore materially compressed when inserted is thereby greatly impaired. into said sockets.

It is the object of this invention to provide The cork sections or blocks 1) impart to the a clutch or brake-shoe of composite construcbrake-shoe increased braking efficiency, and tion which is particularly well adapted,among when heated do not become loose in their 5 other uses, to be employed on steam and elecsockets, but expand under heat and consetric or other railways on which the cars run quently adhere firmly to the walls of the at a high speed, and, by experiment, we have sockets. ascertained that a clutch or brake-shoe com The metal body a of the brake-shoe is cast posed of metal having sockets or openings and the walls of the sockets are not smooth,

5o filled with compressed sections or blocks of but are more or less roughened or uneven, and

.when the cork blocks or sections are forced in their compressed condition into the said sockets the elastic nature of the cork causes it to expand, and the yielding or substantially soft structure of the cork permits it to substantially conform to the roughened surface, so that the cork block or section is in this manner firmly held in its socket,and when the cork is heated in the application of the brake-shoe to the car-wheel it is expanded so that it still further engages the roughened or uneven surfaces or walls of the sockets with increased force, which enables the blocks or sections to be used with brake-shoes having sockets perfectly cylindrical and without the use of locking devices. The soft nature of the cork also augments the adhesion of the brake-shoe to the car-wheel and thereby increases the efficiency of the brake-shoe. In the present instance we have shown the body a of the brake-shoe as provided with a flange I1, having a longitudinal curve 19 adapted to fit the flange of the car-wheel, but we do not desire to limit our invention in this respect, as it is evident that the cork sections may be employed in a body without the flange 1). Ve have also shown the cork sections I) as arranged in substantially a straight line and inserted into sockets, so as to make contact with the portion of the tread of the wheel worn by the rail, but, while we may prefer this construction, we do not desire to limit our invention in this respect, as additional cork sections may be inserted into that portion of the brake-shoe making contact with the tread of the wheel not worn by the rail. The flange b of the brake-shoe shown in Fig. 1 is provided with openings 11 as herein shown, for the passage of dirt, &c., through the shoe.

In Figs. 1 and 2 we have shown a brake shoe for use on'railways, but we do not desire to limit ourselves to the particular form of shoe, as the cork sections 1) may form part of a brake-shoe or clutch of other forms, such, forinstance, as shown in Figs. 3 and 4,wherein the metal body of the brakeshoe is shown as a disk 0, provided with an opening a, which adapts it to be mounted upon a suitable shaft, and having in its face sockets to for the reception of the cork sections 1).

Ve claim- 1. As an improved article of manufacture, a composite brake-shoe consisting of a metal body portion provided with one or more sockets or openings, and a cork block or section fitted into said opening and retained therein by the expansion of the cork in its socket, substantially as and for the purpose specified.

2. As an improved article of manufacture, a brake-shoe provided with a plurality of sockets a and connecting intervening openings a formed in that part of the body portion in line with the portion of the tread of the wheel worn by the rail, and cork sections or blocks inserted into the sockets a in a compressed state, substantially as and for the purpose specified.

3. As an improved article of manufacture, a composite brake-shoe consisting of a body portion provided with a plurality of sockets or openings, and a plurality of compressed cork sections inserted into said sockets or openings and retained therein solely by the expansion of the cork, substantially as described.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

WVILLIAM \V. \VHITCOMB.

FRANK F. COGGIN.

\Vitnesses:

JAs. H. CHURCHILL, J MURPHY. 

